Pneumatic striker action for player pianos



June 1 1926.

A. A. HUS EBY' PNEUMATIC STRIKER ACTION FOR PLAYER PIANOS Filed August 23, 1924 Patented June 1 1926i.v

UNITED STATES OFFICE.

ALBERT HUSEBY, or CHICAGO, rumors.

A lication ind reg-est 2:, 1924. eel-i511 no. 753,672.

This inventionlrel'i'tes to pne'umaftiejstriker ziotions for playe ianos and other pleying musical instruments, end {for ts general object to simplify the construot on, reduce thenu'mbe'r of parts ind oonse'quently the liability of leakage, lesen t'he cost of nianufnoture, and reduce the spacer-equine by thestrjudture. Q'ther more speoitlo objects are, to provide an improved s emr-umt notion which will itecilitrte the n'i'ak ing of repairs Enid renewals, to rovidejen improved construction o fvalve board which Will conthin not only the v'siltfe chambers and 'v'zilt 'es but eleo the air channel, provide animjj roved -striker pineumeti c unit that iney be removably attached to the under side of the valve board and she'll contain in 'its' stationury sicle the usutl Valt'enio't'or diaphragm or pouc and the pressure and me; d1"1'ots thereto from the trzickerrenge tube and the air Channel re'slieet'ii elmto provide an improved closing strip for' 'the air chennehend to provide an improved bleed vent for the under side ot the Valve p'ono'h. I I I ot er objects endiettendei it advehtages of the invention will be epp'arent to fperso jis skilled in the m, esthe same beo'o'mes better understood by re ferenee tothe following detiiiled description, 't'eken in oonneotio'n With the accompanying d diving in which I have illustrzite'dfone practical embodiment er the in. e ntion and wherein Y 7 Fig. 1 is a vertical trehsve ee section through the action on the line 11 of Fig. 9;a d. v i e v Fig. 2 is it top plan viewof it fragment of the Valve boar-d andunde'ilyihg striker pneuniaties. v H v, 7

Referring to the drewing, 5 designates as Y .J .1 alizw an entiretv the valve board which extends the 'full lehgth 'ot' the complete fiction -end is preferably and "as shown formed from a board of siiit'ible thickness vertically 'lma'nterea at intervals et substentilally its transverse center to form valve 'o'hember's "6. Through one edge of the board (the leftas sho n Fig. 1) the bored round duets 7,

inner en s 'of which the: o ppe sin eg of he, end is reoessjed to form a continuous air channel 9, theouter edge or whichis "sea e by eqwogiden dat n strip 10"g1ued thereto end lprefe'rebly termed oni'tsinn'er face With a shallow tongue 11 which enters the channel 9 and maintains the outer edges of theside wells thereof in rigid s'p'ec ed relation. Throrrgh the bottom of the alve board are formed n seri'es of s'hortver- 'ti'cel duots' 12,; each of which communicates et its-upper end with one 01 the horizontal duets The vgi' lye chamber 6 is equipped with the lisiial upper and lower valve seats 13' end 14, respectively, for eo-operzttionwith the usual mushroom vjil ve 15, the spider-shaped stem 16 of which extends downwardly through 21 guide opening 17 in the bottom all or the Valve chamber 6, end is stepped upon the 'nsual valve motor diaphragm or iouoh 18. (r119 an channel 9 communicates with the "suction bellows or reservoir of the instrument so that, while the latter is played, a pertiitl vacuum is maintained in the air channel; and through the bottom Well of the eir ohahhel are fori'ne'da Series of circular openings 19 one for each underlying pneumatio. H v; Gl'ued to the entirefrnider side oi, the valve board 5 is'a paper s t'r'ip or gasket 20, torined fivith openings registering with the severil bottom openings 12, 17 'ttnd 19 of the valve board. Glued to the under side of the ket 2'0 inlaterztljuxtapositioii are the striker pneuniiatie iinits, etiohenibodying the strucme l features illustrated in the sectionel iew, 1. Describing one er these units, 21 designtiteses'zt Whole ereotling'iilzir bl'ocl-z of substantially triangular rot-m in longitudi'nal vertioz'tl section and of a depth or thickness s ili'cientto permit the torinz'ttion therein ofthe ohunibers and ducts thit house endcontrol thefvalv'e poiich 18; said block 21foohstitiiting the stationary side or iii ed Well of the striker pneumatic. To the lower side of the Wideendotth'e' blo-el: 29 is hinged at 22 the movable wall 23 o t' the striker pneuinzt'tig its free end being connected by the usual bellows "cloth 24: to :the correspondin end ot the stationary Well 21, and her- 1. .2 i ing' attached thereto the usual striker arm 25, Through the blool; 21 is 'f'orn'ied a vertioel duct that 'regist'e're with the short vertical duct 12 inthe vel'xfe board, and thereby places the interior of the pneuinetie in continuous communication Withthe Vhlt'e 'chembe'r 6. 1,,

In theiujpper 'ti/ee off the block 21 formed eQoi'reluler' suction johamber 27 Concentric with zind surrounding the valve stem l6, and

directly therebeneath is another smaller circular pouch chamber 28. The diaphragm 18 separates the chambers 27 and 28, being attached atits edges to the annular shoulder 29 formed at the junction of the differential chan'ibers 22' and 28. The upper chamber 27 is formed vith a radial extension 30, the out line form of which is shown in Fig. 2 that underlies and registers with a portion of the circular opening 19 into the air channel 9. 'lhrough the wide end of the block 21 is bored a horizontal duct 31, the outer end of which is closed by a screw plug 32 and washor 33. The inner end 01 the duct 31 communicates with the air channel 9 through a vertical duet 34ithat, at its upper end, cominunicates with the circular opening 19 in the bottom wall of the air channel. From the inner end of the duct 31 a smaller horizontal duct :36 leads into the pouch chamber 25%, and the outer end of this duct- 36 is closed by a thimble cap or plug 37 formed with a central bleed hole 38. 39 designates the tube leading from the tracker range, the lower horizontal end of which is entered into the wide end of the block 91. at one side of the duct 31, ano communicates with a hori zontal duct 40 that leads tangentially into the pouch chamber 28.

The broad operative principle of the apparatus described is the same as that of the standard single valve pneumatic striker action. The air channel 9 is, as stated, in communication with the suction bellows or reservoir of the player action through connections well known in the art and not necessary to be shown, so that a state of partial vacuum continuously exists in said channel. This vacuum acts on the upper side of the pouch 18 through the opening 19, chamber extension 80 and chamber 27, and also upon the lower side of the pouch through the opening 19, ducts 3d and 31, bleed hole 88 and duct 86, so that the valve 15 normally occupies the position shown in Fig 1. V fhen the tracker opening to which the tube 39 is connected is opened by the music sheet, at mospheric pressure is admitted to the chamber 28, lifting the pouch 18, closing valve 15 on its upper seat 13 and raising it from its lower seat 14. This shuts oil atmospheric pressure from the interior of the striker pneumatic and places the latter in communication with the air channel 9, causing the striker pneumatic to collapse. Upon the closure of the tracker opening, the suction in air channel 9 acting through the bleed duct 38 restores the pouch chamber 28 to the same tension as chamber 27, whereupon the valve drops to its normal position.

From the foregoing it will be seen that substantially the lower half of the complete action constitutes a bodily removable unit, so that the entire action may properly be defined as of a semi-unitary character. While the invention involves no novel principle of operation, certain novel structural features thereof present distinct advantages particularly in regard to economy of manufacture and maintenance, and sin'rplicity and conipactness of structure which lessen the liability of leakage and require 1 space in the instrument, and facility o't repairs and renewals. For instance, it will be observed that the valve chambers, the air channel, and the horizontal ducts connecting the valve chambers with the interior oi the pneumatic are all formed in a single integral board, thereby eliminating a large number oi lued joints heretofore employed for the asseun bling of these parts; my improved valve board having only marginal joints tor-mod by the closing strips 8 and 10. By 'lastcning the pneumatics to the bottom of the valve board by a single glued joint, :ach pneumatic can obviously be removed when necessary without disturbing the others or otherwise disassembling the complete action; and in facilitating such removal oi a pneumatic unit from the bottom of the valve board, the presence of the paper gasket is important, since in the withdrawal of the pneumatic by downward pressure at one end, the paper of the gasket readily splits, leaving surfaces favorable for the application of glue when the same pneumatic, or a substitute pneumatic, is reapplied. This is a distinct advantage over a construction wherein two flat wooden surfaces are glued together, since such a joint is very di'llicult to open without splitting or breaking of the parts. Another advantage of locating the air channel 9 in the valve hoard resides in the fact that such a location oi the air channel makes it possible to form and locate the valve motor diaphragm and its pressure and suction control ducts wholly in the removable stationary wall of the strike pneumatic, whereby each valve and its controls can readily be gotten at for inspection, repairs or renewals, by simply removing the striker pneumatic as a unit from the vlvc board 5 in the manner described. rtlso, should any of the bleed ducts 38 become clogged, they are readily gotten at and removed by simply taking out the plugs 32 without requiring any turth dismantling of the structure.

I claim-- 1. In a pneumatic player action, a valve board comprising an integral wooden structure hollowed out to provide valve chambers, ducts for connecting said valve chambers with striker pneumatics, and a continuous longitudinal air channel formed as a groove in one edge of said structure, and a closure strip glued to said edge to seal said air channel and forming an edge portion of said valve board.

2. In a pneumatic player action, a valve i r is board comprising an integral wooden structure hollowed out to provide valve chambers, transversely disposed ducts on one side of said valve chambers for connecting the latter with striker pneumatics, and a continuous longitudinal air channel on the opposite side of said valve chambers formed as a groove in one edge of said structure, and a closure strip glued to said edge to seal said air channel and forming an edge portion oi said valve board.

3. In a pneumatic player action, a valve board. comprising an integral wooden structure of rectangular cross-section bored to provide round vertically disposed valve chambers and transversely disposed ducts on one side of said valve chambers for connecting the latter with striker pneumatics, and grooved in one edge to form a continuous longitudinal air channel on the opposite side of said valve chambers, and a closure strip of a width equal to the thickness of said structure glued to the grooved edge of the latter and forming an edge portion of said board.

s. In apneumatic player action, a valve board comprising an integral wooden board bored to provide round vertically disposed valve chambers and transversely disposed ducts on one side of said valve chambers for connecting the latter with striker pneumatics, and grooved in one edge to form a continuous longitudinal air channel on the opposite side of said valve chambers, and a closure strip glued to the grooved edge of said board and formed with a tongue projecting into the open side of said air channel groove between the top and bottom walls thereof.

5. In a pneumatic player action, a valve board comprising an integral wooden structure hollowed out to provide valve chambers, ducts on one side of said valve chambers for connecting the latter with striker pneumatics, a continuous longitudinal air channel on the opposite side of said valve chambers, ducts in the bottom wall of said air channel for connecting the latter with the valve-actuating diaphragm of the striker pneumatics, and a closure strip sealing one side of said air channel.

6. In a pneumatic player action, the com-. bination of a valve board containing valve chambers and an air channel extending along one side of said valve chambers, upper and lower valve seats in said valve chambers, valves in said valve chambers having their stems extending through the bottom of said valve board, and striker pneumatics each having a stationary wall of substantially triangular form in vertical longitudinal section attached to the under side of said valve board; each of said stationary sides formed with a suction chamber having a lateral extension registering with said air channel through the bottom of the latter and a pouch chamber, a valve-actuating pouch separatin said chambers, a duct connecting said pouch chamber with a tracker tube through the thicker portion of said stationary wall,

and a bleed controlled duct connecting said pouch chamber with said air channel through the thicker portion of said stationary wall.

7. in a pneumatic player action, the combination of a valve board containing a row of valve chambers substantially mid-width thereof, a longitudinally extending air channel on one side of said valve chambers, and transv rsely extending ducts COHllDUlllCZlting with the opposite sides of said valve chambers, and opening through one edge of said board, a strip glued to the said edge and sealing the outer ends of said transversely extending ducts,upper and lower valve seats in said valve chambers, valves in said valve chambers having stems extending through the bottom of said board, and striker pneuinatics having their stationary sides attached to the under side of said valve board; each of said stationary sides formed with a suction chamber having a radial extension connnunicating with said air channel and a pouch chamber and ducts communicating one with a tracker tube and the other with a bleed vent to said air channel, a valve-actuating pouch separating said chambers, and a duct connecting a transversely extending duct of said valve board with the interior oi the pneumatic.

A LBERT A. HUSEBY. 

